Getting DXBall to run

[Hans Leidekker]

Hi,

I have this old breakout style game called DXBall (I think 
it's a DirectX 2 game) that runs flawlessly but for one
page fault after the second startup screen, right before
the first level starts. You can download the game here:

http://www.magicwandsoft.com/games/dxball/download.html

I traced it down to dlls/ddraw/dsurface/dib.c:create_dib where
it says:

if (!This->surface_desc.lpSurface) {
        This->surface_desc.lpSurface = priv->dib.bitmap_data;
        This->surface_desc.dwFlags |= DDSD_LPSURFACE;
    }

I don't see why This->surface_desc.lpSurface is being tested
here before doing the assignment since up in the function 
there's this assert statement:

assert(This->surface_desc.lpSurface != NULL);

And as far as I can tell there's nothing in between that could
change the value of This->surface_desc.lpSurface, so this code
will never be reached. Some extra traces confirm that this is 
the case.

If I make the assignment unconditional the game starts to run, 
but I'm not really sure if this fix hides another bug or not. 
Maybe some DirectX guru can tell right away?

-Hans

Changelog:
    Remove superfluous NULL check